Simple copper tube design for continuous casting process with enhanced rigidity

ABSTRACT

A mold for use in a continuous caster is provided that includes a tubular structure having a plurality of wall structures. Each of the outer faces of the wall structures is configured to have reduced thicknesses centrally located between corners of the wall structures so as to provide rigidity to the tubular structure for handling thermal loads during a continuous casting process.

BACKGROUND OF THE INVENTION

The invention is related to the field of continuous casting, and in particular to a tube structure that can be used in a continuous casting process.

Continuous casting is a process that transforms molten metal into solid on a continuous basis and includes a variety of important commercial processes. These processes are the most efficient way to solidify large volumes of metal into simple shapes for subsequent processing. Most basic metals are mass-produced using a continuous casting process, including over 1 Billion tons of steel, 20 million tons of aluminum, and 1 million tons of copper, nickel, and other metals in the world each year.

Continuous casting is distinguished from other solidification processes by its steady state nature, relative to an outside observer in a laboratory frame of reference. The molten metal solidifies against the mold walls while it is simultaneously withdrawn from the bottom of the mold at a rate which maintains the solid/liquid interface at a constant position with time. The process works best when all of its aspects operate in this steady-state manner.

Moreover, continuous casting generally has a higher capital cost, but lower operating cost. It is the most cost- and energy-efficient method to mass-produce semi-finished metal products with consistent quality in a variety of sizes and shapes. Cross-sections can be rectangular, for subsequent rolling into plate or sheet, square, rectangular or circular for long products, and even “dog-bone” shapes, for rolling into I or H beams.

Many times vertical machines are used to cast steel for big blooms and aluminum and a few other metals for special applications. Curved machines are used for the majority of steel casting and require bending and/or unbending of the solidifying strand. Horizontal casting features a shorter building and is used occasionally for both nonferrous alloys and steel. Finally, thin strip casting is used for steel production and other metals in low-production markets in order to minimize the amount of rolling required.

Many casting processes for long products (billets/blooms) use conventional copper tubes. These copper tubes could undergo: permanent deformation (plastic distortion), wearing on the bottom part and cracking on the meniscus area. The invention provides a solution to address these problems.

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided a mold for use in a continuous caster. The mold includes a tubular quadrilateral structure having four walls joined at four corners. Each of the walls have inner and outer faces configured to provide the walls with reduced thicknesses centrally located between the corners.

According to another aspect of the invention, there is provided a mold for use in a continuous caster. The mold includes a tubular structure having a plurality of wall structures. Each of the outer faces of the wall structures is configured to have reduced thicknesses centrally located between corners of the wall structures so as to provide rigidity to the tubular structure for handling thermal loads during a continuous casting process.

According to another aspect of the invention, there is provided a method of producing a mold for use in a caster. The method includes providing a tubular structure that includes a plurality of wall structures. Also, the method includes arranging each of the outer faces of the wall structures to have reduced thicknesses centrally located between corners of the wall structures so as to provide rigidity to the tubular structure for handling thermal loads during a continuous casting process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an embodiment of a tubular casting mold used in a continuous casting process;

FIG. 2 is a schematic diagram illustrating an embodiment of the tubular casting mold having an outer face shaped in a concave configuration using an arc;

FIG. 3 is a schematic diagram illustrating an embodiment of the tubular casting mold having an outer face shaped in a concave configuration using an ellipse sector;

FIG. 4 is a schematic diagram illustrating an embodiment of the tubular casting mold having an outer face shaped in a concave configuration using an hexagon or octagon sector;

FIG. 5 is a schematic diagram illustrating an embodiment of the tubular casting mold having single plates; and

FIGS. 6A-6B are schematic diagrams illustrating the side and cross-sectional view of an embodiment of the tubular casting mold 56 where the concave configuration is applied in a particular region of the mold length.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides a novel design for a tubular casting mold used in a continuous casting process. The tubular casting mold includes externally on each side a concave configuration that is shaped by arch or by other geometrical shapes. Each side of the tubular structure acts as very rigid bridge or tunnel configuration withstanding high thermal loads without permanent deformations.

FIG. 1 shows an embodiment of a tubular casting mold 2 used in a continuous casting process. The tubular casting mold is made of copper or similar materials and includes 4 walls joined at four corners 6. Note the tubular structure can be a tubular quadrilateral in other embodiments of the invention. Each of the walls 4 having an inner 8 and outer faces 10 configured to provide the walls 4 with reduced thickness 12 centrally located between the corners 6. The outer faces have a concave configuration while the corners 6 have a defined reduced thicknesses centrally located between corners 6 of the walls 4. The extension 14 of the concave shape is selected to optimally provide rigidity to the tubular casting mold 2 for handling thermal loads during casting. The inner faces 8 can include any defined shape, such as a rectangular, square, or parallelogram.

The tubular casting mold can be comprised of copper or other similar materials. The thinner outer faces 10 are possible due to the rigid concave configuration. The thinner outer faces 10 are thinner relative to the corners 6. This way temperature of an outer face 10 is decreased considerably, reducing as a consequence the permanent deformation, the wearing, and cracking sensitivity of the tube, as an example.

In other embodiments of the invention the concave configuration can be formed using other geometrical shapes.

FIG. 2 shows an embodiment of the tubular casting mold 18 used in a continuous casting process having an outer face 20 shaped in a concave configuration using an arc. The arc includes a single radius R. FIG. 3 an embodiment of the tubular casting mold 24 used in a continuous casting process having an outer face 26 shaped in a concave configuration using an ellipse sector 28. FIG. 4 an embodiment of the tubular casting mold 30 used in a continuous casting process having an outer face 32 shaped in a concave configuration using part of a hexagon or an octagon.

FIG. 5 is a schematic diagram illustrating an embodiment of the tubular casting mold having single plates. The plates 40-46 are coupled together to form wall structures. The plates both have inner 48 and outer 50 faces and form a concave configuration as described herein on their outer faces 50. The plates can include materials such as copper or copper alloy, metals, or the like. The plates could be connected by bolts on the corners or similar methods or by an external steel sleeve that keep the plates tight together.

FIGS. 6A-6B are schematic diagrams illustrating the side and cross-sectional view of an embodiment of the tubular casting mold 56 where the concave configuration is applied in a particular region of the mold length. In this case, the mold includes a concave configuration in a region 58 of the mold 56 length that includes its meniscus area 60 where the thermal load are maximum. Note the concave configure is only applicable for the meniscus area 60 while the rest of the mold 56 will have a conventional design. Note other regions on the mold length can be used to form a concave configuration.

Note the invention can be designed using the extrusion of copper or hydroforming manufacturing process as well as other techniques utilized in the art to form casting molds.

The inventive tubular casting mold design described herein intends to provide an appearance similar to a conventional tubular casting mold but the enhanced rigidity and low temperatures are the key fundamental features distinguishing the inventive tubular casting mold. The manufacturing costs of the inventive design are low as compared to a conventional tube because there is no need for any additional operation of machining during the manufacturing process. According to one technique, the manufacturing of the inventive design may be accomplished by extrusion of copper or hydroforming.

Although the present invention has been shown and described with respect to several preferred embodiments thereof, various changes, omissions and additions to the form and detail thereof, may be made therein, without departing from the spirit and scope of the invention. 

What is claimed is:
 1. A mold for use in a continuous caster, said mold comprising: a tubular quadrilateral structure having four walls joined at four corners, each of the walls having inner and outer faces configured to provide the walls with reduced thicknesses centrally located between the corners.
 2. The mold of claim 1, wherein the inner faces define a parallelogram.
 3. The mold of claim 1, wherein the outer faces are concave.
 4. A mold for use in a continuous caster comprising: a tubular structure that includes a plurality of wall structures, wherein each of the outer faces of the wall structures is configured to have reduced thicknesses centrally located between corners of the wall structures so as to provide rigidity to the tubular structure for handling thermal loads during a continuous casting process.
 5. The mold of claim 4, wherein the wall structures comprises four walls joined at four corners.
 6. The mold of claim 4, wherein the tubular structure comprises copper.
 7. The mold of claim 4, wherein the outer faces is defined by a concave configuration.
 8. The mold of claim 8, wherein the concave configuration is defined by an arc having a defined radius.
 9. The mold of claim 8, wherein the concave configuration is defined by an ellipse sector.
 10. The mold of claim 8, wherein the concave configuration is defined by a hexagon or octagon.
 11. The mold of claim 8, wherein the concave configuration is defined by a selected shape.
 12. The mold of claim 4, wherein the wall structures comprise plate structures.
 13. The mold of claim 4, wherein the concave configuration is applied on a selective region on the length of the mold.
 14. The mold of claim 4, wherein the tubular structure is formed by extrusion of copper or hydroforming.
 15. A method of producing a mold for use in a caster comprising: providing a tubular structure that includes a plurality of wall structures; and arranging each of the outer faces of the wall structures to have reduced thicknesses centrally located between corners of the wall structures so as to provide rigidity to the tubular structure for handling thermal loads during a continuous casting process.
 16. The method of claim 15, wherein the wall structures comprises four walls joined at four corners.
 17. The method of claim 15, wherein the tubular structure comprises copper.
 18. The method of claim 15, wherein the outer faces is defined by a concave configuration.
 19. The method of claim 18, wherein the concave configuration is defined by an arc having a defined radius.
 20. The method of claim 18, wherein the concave configuration is defined by an ellipse sector.
 21. The method of claim 18, wherein the concave configuration is defined by a hexagon or octagon.
 22. The method of claim 18, wherein the concave configuration is defined by a selected shape.
 23. The method of claim 15, wherein the wall structures comprise plate structure.
 24. The mold of claim 15, wherein the concave configuration is applied on a selective region on the length of the mold.
 25. The mold of claim 15, wherein the tubular structure is formed by extrusion of copper or hydroforming. 